Makefile: Error1

Question

I have a very simple c programme:

int main()
{
  return(1);
}

and a simple Makefile:

all:
    gcc -ansi -pedantic -o tmp tmp.c
    ./tmp

However, when I type make I get the following error message:

$ make
gcc -ansi -pedantic -o tmp tmp.c
./tmp
make: *** [all] Error 1

What obvious thing am I missing?

Answer 1

You're returning an error code of 1 from your application. It's Make's job to report this as an error!

Answer 2

This is because your program is returning 1.

Makes does the compilation using gcc, which goes fine (returns 0) so it proceeds with the execution, but your program return a non-zero value, so make reports this as an error.

A program on successful completion should return 0 and return a non-zero value otherwise.

Answer 3

Make exits with an error if any command it executes exits with an error.

Since your program is exiting with a code of 1, make sees that as an error, and then returns the same error itself.

You can tell make to ignore errors by placing a - at the beginning of the line like this:

-./tmp

You can see more about error handling in makefiles here.